QuakeLive isn't Quake 3.
They've rewritten a fair chunk of code, fixed many flaws and exploits of the engine, improved the graphics and built in unlagged code.
Not to mention the main point behind the project, running it via a web browser, with wordwide global player statistics.
The quake communities died off as only dedicated fans paid for servers, with this business model it should stay running as long as players want to play, without decreases in service level or lack of updates, there is no 'ship-and-run'.
It's completely free to get an account and play on 50 odd maps and 9 game modes, paid accounts get access to new 20 new maps, Freezetag and some other things. Parts of the paid accounts will probably trickle down to the free accounts later when premium accounts get more updates.
to see the state of the community.